1. Field of the Invention
The invention relates to a modular cage for an electronic component, and in particular, to a modular cage formed from a plurality of standardized walls that can be joined together to create a variety of configurations for accommodating a variety of different number of electronic components therein.
2. Background Information
Electronic components, such as direct access storage devices (DASDs), for example, are typically individually disposed within a so-called xe2x80x9csledxe2x80x9d or tray, which in turn is mounted in a housing or cage containing many DASDs. The cage helps to position and align the individual DASDs relative to a backplane, to which the DASDs are connected in a known manner.
The known cage is typically formed from sheet metal, by bending the sheet metal to form the walls of the cage, or by fastening the sheet metal walls together using conventional means. The sheet metal of the cage is typically connected to a ground potential. Thus, during installation or removal of the DASD, the cage reduces the risk of damage to the DASD due to static electricity by electrically coupling the DASD to the cage to discharge static electricity. As is well known, static electricity may destroy sensitive circuitry of the DASD.
Moreover, while in operation, the DASDs are routinely subjected to mechanical vibration and shock. The DASDs have heads that could malfunction or be damaged by the mechanical vibration or shock while the DASDs are running. Moreover, vibrations can cause so-called soft errors in the reading of data. That is, the heads of the DASD need to be properly aligned and positioned in order to read data from a media source. Vibrations can prevent the proper tracking of the head, causing the head to xe2x80x9cre-readxe2x80x9d the media several times in order to acquire the data. Thus, vibrations can reduce the operational speed of the DASD. However, sheet metal has relatively poor damping qualities. Thus, the known sheet metal cages do not significantly dampen vibrations. There is thus a need for a cage that has high damping attributes, so that vibrations are reduced.
It is also known to provide a sheet metal laminate known as CLD (constrained layer dampener), to help reduce vibrations. However, the process for making such a laminate is relatively time consuming and expensive. Thus, there is a need for a panel that can reduce vibrations, but that can be easily, quickly and cheaply incorporated into a cage.
Further, it is known to provide the DASD tray with springs that engage with the sheet metal roof member and floor member of the cage. The springs are used to reduce vibrations, and to hold the DASD tray in position. However, the sheet metal of the cage has a tendency to flex. As such, the springs may push the roof member and floor member away from each other, so that the springs are not held under an optimum compression. Further, it is difficult to manufacture the known cage to dimensionally accurate measurements. Thus, even without the flexing of the sheet metal, the spacing between the roof member and the floor member may not be ideal, and the springs may not be held under their optimum compression. As such, the springs may not sufficiently reduce vibrations and/or hold the DASD tray in the preferred position.
Additionally, the sheet metal walls of the cage are typically positioned relative to each other with a high degree of tolerance. However, the cage is also typically used to guide the DASD into engagement with the backplane. Thus, the conventional cage may cause a misalignment between the DASD and the backplane, preventing a positive coupling therebetween, and possibly damaging the connectors used to couple the DASD to the backplane. Therefore, there is a need for a cage that can be manufactured to precise dimensions, and that is relatively rigid, so that the resulting cage provides for dimensionally accurate guidance and increased stability of the associated DASD.
Furthermore, a DASD is typically utilized in a computer system that includes numerous electrical components that tend to generate a substantial amount of heat. Moreover, the DASD itself generates heat while operating. Because excess temperature can impair an electrical component""s reliability and functionality, computer systems are typically provided with blowers that cause a cooling flow of air to pass through the cage and over the various electrical components, thus causing a transfer of heat away from the electrical components. Thus, there is a need for a cage that allows for an increased flow of cooling air therethrough, without reducing the structural integrity of the cage.
Furthermore, the conventional cage is typically tailored to hold a specific number of DASDs, for example six. Although fewer DASDs may be positioned within the conventional cage, the size of the cage remains constant. Thus, the cage tailored for six DASDs, but which is used to accommodate only two DASDs, for example, will take up extra space, that could otherwise be used to house other components. Alternatively, specific cages can be tailored to hold a precise number of DASDs. Thus, if only two DASDs are to be used, a smaller, specifically tailored DASD cage could be utilized. However, as will be appreciated, this requires a larger number of cage components to be kept in stock, which increases inventory. Moreover, each different DASD cage will need its own specific tooling in order to make the cage, thus increasing the manufacturing costs. Thus, there is a need for a cage that can be easily modified to allow for a different number of DASDs to be received therein, while occupying a minimal amount of space.
It is, therefore, a principle object of this invention to provide a modular cage for an electronic component.
It is another object of the invention to provide a modular cage for an electronic component that solves the above mentioned problems.
These and other objects of the present invention are accomplished by the modular cage for an electronic component disclosed herein.
Advantageously, according to one aspect of the present invention, the cage according to the present invention is formed by a first wall, a second wall, a floor member, and a roof member. In an exemplary aspect of the present invention, the first and second walls are identical to each other. That is, the same member can be used for either the first wall or the second wall. This advantageously reduces the total number of different parts that needs to be manufactured for the cage, thus reducing tooling times and costs, and reducing inventory.
In an exemplary aspect of the present invention, the first and second walls are manufactured by casting. This technique allows the walls to be made more quickly and cheaply, and with a greater mass than the sheet metal walls of the known cages. Thus, the resulting walls will be relatively solid, with a thickness of about 2 to 3 mm., for example, and will resist vibrations and flexing due to externally applied forces. Moreover, the cast walls can be manufactured to a higher degree of dimensional accuracy than the known sheet metal walls. Thus, the resulting cage will more accurately align and guide the DASDs into engagement with an associated backplane, for example, as compared to a conventional sheet metal cage.
Moreover, casting the walls advantageously allows various features of the walls to be cast directly therein, thus increasing the production output. Moreover, casting the walls provides for a wall that is dimensionally repeatable, that is, each wall will be substantially identical to the other walls. Thus, a cage manufactured using cast walls is believed to be more dimensionally accurate than a cage manufactured using sheet metal.
In a further exemplary aspect of the present invention, the first and second walls are formed from a material that exhibits good vibrational control, for example, zinc aluminum.
Moreover, each wall preferably has a configuration that will allow a standard DASD tray to be accommodated within the cage, in a preferred orientation, i.e., with the DASD tray and DASD arranged essentially parallel to the walls.
In a further exemplary aspect of the present invention, the walls are provided with a plurality of ribs on a surface thereof. Using ribs will allow the walls to be made thinner, thus requiring less material for the formation of the walls, while increasing the production rate of the walls by reducing casting times.
In another exemplary aspect of the invention, both the roof member and floor member include a panel formed from a prefabricated damped metallic laminate (DML). As is known, a damped metallic laminate is a laminated sheet metal material that is typically used in the automotive industry, and which exhibits good damping qualities.
In a further aspect of the present invention, the panel can be stamped or machined to include features to accommodate various system needs. This allows the cage to be easily modified for different applications, while retaining the modularity of the various components of the cage.
In an exemplary embodiment of the present invention, the roof member and the floor member each include a stiffener plate provided adjacent to the respective panels. The stiffener plates are used to increase the structural rigidity of the roof member and floor member. The stiffener plates ensure that the DASD tray, which may be provided with springs on its upper and/or lower edges, engages with the roof member and the floor member without flexing of the roof member or floor member. Thus, the springs of the DASD tray will be under optimal compression at all times, ensuring accurate alignment of the DASD and minimizing vibrations thereof.
Advantageously, the stiffener plates may be provided with features that allow other components to be attached to the cage, or which allow the cage to be easily adapted to different hardware systems. This increases the flexibility and adaptability of the cage for different applications, without interfering with the modularity or functionality of the cage.
The width of the roof member and floor member define a size of the cage. For example, if the cage is adapted to accommodate two DASDs, then the roof member and floor member will have a relatively small width, so that a relatively narrow cage will be formed. On the other hand, if the cage is adapted to accommodate more than one DASD, for example, six DASDs, the roof member and floor member will have a significantly greater width, so that a relatively wide cage will result. As will be appreciated, the present invention can thus be modified to accommodate any number of DASD trays in a simple and inexpensive manner. Moreover, although the present invention has been shown to be particularly useful in accommodating DASDs and the associated trays, it is contemplated that the present invention can be utilized in a variety of applications, for example, whenever a variety of different sized cages may be needed.
In summary, due to the modular first and second walls, the cage according to the present invention can be accurately made, without dimensional variations in the manufactured cages. As such, the cage will accurately align the DASD relative to the backplane, as these two components are plugged together.
Further, the cast walls allow the height of the cage to be held within close tolerances. Thus, each resulting cage will hold the springs of the DASD tray at an optimal compression.
Moreover, the cage can be modified in size and application using a minimal amount of design time and necessary tooling. That is, the same walls can be used for a large number of differently configured cages, by merely using different panels and stiffener plates for the roof member and floor member. Thus, a differently configured cage can be built on the manufacturing floor.
Further, a variety of mounting features can be utilized with the cage, simply by modifying the stiffener plates in an appropriate manner, without affecting the operational characteristics of the cage. That is, the vibration damping features of the present invention are determined primarily by the cast walls, and the DML panels.
Moreover, the cage significantly reduces vibrations that may otherwise affect the operation of the direct access storage device. Thus, a direct access storage device utilized in a cage manufactured in accordance with the present invention will be subjected to fewer soft errors, thus increasing the operational speed of the device.